The invention concerns a water heater for gaseous or gasified liquid fuels, especially for installation in mobile accommodation such as mobile homes, caravans or in mountain huts or similar small rooms, having a closed water container of approximately circular cross-section, a housing surrounding at least the lower section of said water container, said housing being closed at the bottom by means of a base and forming, in conjunction with the base of the water container, a gas-tight combustion chamber, a lower induction aperture for fresh air and an upper extraction aperture for waste gases and also passages through the water container for inlet and outlet pipes.